1. Field of the Invention
The present invention relates to a method and apparatus for producing a handled bag having a top edge which is free of discontinuities and irregularities. In particular, the present invention is directed to a method and apparatus for producing a handled bag from a web of sheet material by creating perforated seams transversely across the web, and attaching handles proximate the perforated seams so to extend beyond the top of each bag when the perforated seam is broken. The present invention is further directed to a method and separating device for efficiently breaking perforated seams using a set of synchronously rotating first and second breaker rolls.
2. Description of the Related Art
Handled bags are produced and sold in a variety of configurations and sizes. Perhaps one of the most popular of these configurations is a "self-opening square" bag having a twisted paper rope handle. These handled bags are frequently used in department stores, shopping malls, and fashion boutiques. Typically, the bottom of the self-opening square bag is folded on to the top side or seam side of the bag.
FIG. 1 schematically illustrates a common method of producing handled bags 50' having two U-shaped handles 40'. Conventionally, four cross cut segments A are first provided in a spaced relationship across a web of sheet material 10'. The spaced relationship of the four cross cut segments A must be predetermined, so as to correspond with the placement of two handles 40' which are subsequently affixed to the web 10'. The web 10' is then folded and flattened with the opposite longitudinal edges 11' of the web being joined to form a tubular configuration. The conventional handled bag producing method then requires that a second series of cross cuts B be provided across the web 10' in alignment with the initial four cross cut segments A to separate the tubular bag section from the web 10'. Subsequently, the bottom end of the tubular bag section is closed to complete production of the handled bag 50'.
In actuality, however, it has been observed that the second series of cross cuts B are frequently provided in a spaced or misaligned relationship relative to the initial four cross cut segments A. This creates an unappealing, jagged edge along the top of the bag 50'. Likewise, it has been observed that the attached handles 40' are often misaligned, severed or detached upon completion of the conventional handled bag producing method. This has been known to result in jamming or malfunctioning of the handled bag producing apparatus. These undesirable results are typically due to tolerance limitations in conventional machinery and inherent spacing discrepancies resulting from slack or tension in the web. Hence, there is a need for a method and apparatus for efficiently producing a handled bag having a continuous, substantially smooth top edge which may be performed automatically and provides predictable results.
Further examples of known bag producing methods are demonstrated by U.S. Pat. No. 3,040,633 issued to Davis; U.S. Pat. No. 3,143,936 issued to Becker; U.S. Pat. Nos. 3,464,325 and 3,494,264 issued to Class; and U.S. Pat. No. 3,722,377 issued to Hayes. Likewise, handled bag producing apparatus are shown by U.S. Pat. No. 2,844,075 issued to Davis et al.; U.S. Pat. No. 2,847,914 issued to Davis.; U.S. Pat. No. 2,855,832 issued to Mengis; U.S. Pat. No. 3,481,256 issued to Hayes; and U.S. Pat. No. 3,850,724 issued to Lehmacher. Additional bag making methods and apparatus are shown by U.S. Pat. No. 3,203,323 issued to Adams et al.; U.S. Pat. No. 4,069,964 issued to Willet et al.; U.S. Pat. No. 4,480,752 issued to Jacobs; U.S. Pat. No. 4,088,264 issued to Voqt; and U.S. Pat. No. 5,040,904 issued to Cornwell. However, these bag producing methods and apparatus have not necessarily proven to be effective in satisfying the needs of the handled bag producing art.